Both are good choices. The advantage of the S&W is that it can be held in the hand, inspected and bought locally. The advantages of the PSA is it will come with a dust cover and forward assist (typically), can be carbine/mid-length/rifle gassed, can have a stainless/melonited/chromed barrel and also can come with some upgraded furniture.
There is nothing wrong with a stainless barrel if you don't plan on shooting thousands a year through it. It won't last as long as a melonited of chrome lined barrel (which only cost a little more), but it won't wear out all that fast either. Freedom line Stainless barrels aren't exactly match grade either (though I do get sub-moa out of mine with handloads), but are quality products. All things equal though, the stainless barrel is going to perform about the same as any other unlined barrel. It will just be a different color. I don't think there has ever been any evidence that an entry level unlined barrel of one material has performed noticeably different than a equivalent barrel of another material.
And honestly, even though Chrome lining or meloniting is very cost effective when looking at the overall price, the sometimes forgotten reality is that people who can afford to wear out barrels can also afford to replace them.